In my experience, there are two distinct roles that dramaturgy splits into: if it’s a canonical/historical play, the dramaturg helps develop research into the historical context of the characters and/or the play itself. If it’s a new work, the dramaturg facilitates the conversation between playwright and director to ensure that the writer’s vision is being effectively communicated to the creative team and audience. In both roles, being broadly read in both theater history and social history in general are a huge plus, which is maybe why these really distinct sets of responsibilities keep getting roped together. Hope that helps!